Re: [RFC PATCH 1/5] OMAP3:I2C: Add device tree nodes for beagle board

Grant Likely
2011-07-20T18:55:13Z

On Wed, Jul 20, 2011 at 07:04:20PM +0800, Shawn Guo wrote:
> > Mostly consistency. Most of the experience we have with the flattened
> > device tree up to this point hasn't bothered with the 'status'
> > property. It is only when AMP and hypervisors cam online that it
> > became important to use a status property, and that only when the
> > kernel needs to be told that the device does indeed exist, but it must
> > not be touched. I'd like to continue that pattern for new DT users
> > with the default assumption that a device is enabled unless the board
> > .dts explicitly disables it.
[...]
> Besides the bothering that we have to list so many unused controllers
> in individual board dts file, it's also hard to tell which controllers
> are actually available on the board. People have to look at imx53.dts
> to get a full list and then exclude the ones in imx53-<board>.dts as
> "disabled".
>
> And if we go the way opposite, adding "disabled" status for everyone
> in imx53.dts, we will only need to specify the peripherals that are
> actually available on board with "okay" status in imx53-<board>.dts.
> And it's much more clear for people to see what peripherals are
> available on individual board.
>
> So I'm going the way than you suggested. Please let me know if you
> strongly dislikes it.

Yes, I strongly dislike it. I understand the concern, but at this
early stage with converting to device tree I think consistency between
platforms is more important. We can talk about the issue at Linaro
Connect in 2 weeks, but in the mean time please use the
enabled-by-default/explicitly-disabled pattern.

g.